Oh, god! Why am I so tall!

This just in: Tall people get cancer at higher rates than short people. Apparently this is already known in the epidemiological world, but it's news to me (Shocking news! Time to panic news!).

A study just released in the Lancet looked into the impact of height on the development of several common cancers, and found a significant and positive association between height and cancer incidence that was consistent across genders and cultures. For a large sample of British women, they also found a "clear and highly significant trend of increasing cancer risk with increasing height" even after controlling for confounding factors like age, region, socioeconomic status, smoking, alcohol intake, body-mass index, strenuous exercise, age at menarche, parity, and age at first birth. Just look at this graph of adjusted relative risks (RRs) per 10 CM in height and 95% floated confidence intervals (FCI) for total incident cancer (among the British women), by height (in CM). Not that I have a full grasp on what is actually graphed here, but the trend is clear: more height, more cancer.  I've helpfully pointed out the relative risk (odds?) of cancer for my own height. It's at the top of the graph! Oh god!

The authors of this study offer several possible explanations as to why tall people get more cancer:

The similarity of the height-associated RR for different cancers and in different populations suggests that a basic common mechanism, possibly acting in early life, might be involved. Adult height reaches its maximum between the ages of 20 and 30 years. Variation in height relates to genetic and environmental influences acting mostly in the first 20 years, or so, of life; environmental factors, including childhood nutrition and infections, are believed to predominate. Hormone levels, especially of growth factors such as insulin-like growth factors (IGFs), both in childhood and in adult life, might be relevant. Circulating levels of IGFs in adulthood and childhood affect cancer risk; IGF-I levels in childhood and adolescence are strongly related to skeletal growth, and levels in adulthood, although less strongly, to adult height.

Another possibility is that height predicts cancer risk because taller people have more cells (including stem cells), and thus a greater opportunity for mutations leading to malignant transformation. Height might thus be related to cancer risk through increased cell turnover mediated by growth factors, or through increased cell numbers. The relation between height and cancer risk might underlie part of the difference in cancer incidence between populations, and changes in cancer incidence over time. Adult height in European populations has increased by about 1 cm per decade throughout the 20th century. The increase in adult height during the past century could thus have resulted in an increase in cancer incidence some 10–15% above that expected if population height had remained constant. This assumes, of course, that the effect of height is independent of changes in other risk factors.

I do not like this. Not one bit.  It's like I'm being punished for drinking all that milk and eating all those vegetables while I was growing up. Bah!